Updated version number

Author: sergioteula

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
     name='python-amazon-paapi',
-    version='4.1.1',
+    version='4.2.0',
     author='Sergio Abad',
     author_email='[email protected]',
     description='Amazon Product Advertising API 5.0 wrapper for Python',